Phenotypic and molecular characterization of different isolates of Lactobacillus plantarum from four Nigerian fermented foods for use as probiotics in aquaculture

This study aimed at identifying Lactobacillus plantarum from fermented maize, sorghum, soyabeans and cassava, using both phenotypic method and 16S RNA sequencing, as well as determining similarity or otherwise among recovered isolates. Biochemical characterization of isolates recovered from these fermented foods revealed that L. plantarum occurred in all fermented food examined, with slight variation in their abilities to ferment some sugars (arabinose, dulbitol and mannitol). These phenotypically identified isolates were also confirmed to be L. plantarum by 16S rRNA sequencing, having close relatedness (≥ 95%) with other isolates available in the gene bank. However, intragenomic heterogeneity of the 16S rRNA gene was observed among these L. plantarum isolates. The result obtained in this finding pinpoints the need to evaluate the beneficial effects each strain of L. plantarum may possess as promising probiotics, rather than generalising common effects for all strains of this bacterial species.